class FrontEndDeveloper {
  public:
    void developFrontEnd() {}
};

class BackEndDeveloper {
  public:
    void developBackEnd() {}
};

class MiddlewareDeveloper {
  public:
    void developMiddleware() {}
};

class Project {
  public:
    void deliver() {
      fed_.developFrontEnd();
      med_.developMiddleware();
      bed_.developBackEnd();
    }
  private:
    FrontEndDeveloper fed_;
    MiddlewareDeveloper med_;
    BackEndDeveloper bed_;
};


int main (int argc, char *argv[]) {
  auto new_project = Project{};
  new_project.deliver();
  return 0;
}
